[Numpy-discussion] tofile problems

[Paul Probert]

All,
   I'm trying to write numpy arrays as binary data, to support a legacy 
file format.  So I open a file and write to it:

fp = open('somefile','w')
...
oldpos = fp.tell()
somenumpyarray.tofile(fp)
newpos = fp.tell()
diff = newpos - oldpos - somenumpyarray.nbytes
if diff != 0:
   print 'ahhah! mismatch=',diff
...

I'm observing that every once in while I get 'ahhah! mismatch=1', that 
is, the file position is advanced by one more byte than x.nbytes would give.
I'm using 1.4.1 on windows, python 2.5.
Any ideas?


Thanks,
Paul Probert
University of Wisconsin